Regulated pump with constant displacement volume

ABSTRACT

A pump has a housing with a housing ring, a rotor with pistons, and a control ring between the housing ring and the rotor so that a working space is formed between the rotor and the control ring, and an annular space is formed between the control ring and the housing ring. The annular space is divided into first and second control spaces, connected by throttling means. The first control space receives high pressure fluid, and the second control space discharges into a consumer line. When at high rotary speed, the pressure differential becomes great, the control ring is displaced to reduce the working space so that a substantially constant volume is pumped at different speeds. A compensating device responds to the pressure in the consumer line to urge the control ring to increase the working space so that the influence of the fluid pressure and of the piston friction on the control ring is compensated.

United States Patent [191 Dworak et a1.

[451 July 3, 1973 REGULATED PUMP WITH CONSTANT DISPLACEMENT VOLUME [73]Assignee: Robert Bosch Gmbl-l, Stuttgart,

Germany [22] Filed: Apr. 1, 1971 [21] Appl. No.: 130,288

[30] Foreign Application Priority Data Apr. 2, 1970 Germany P 20 15744.2

[52] US. Cl 417/220, 418/26, 418/30 [51] Int. Cl. F04b 49/00 [58] Fieldof Search 91/475, 486; 417/213, 219, 220, 221; 418/27, 30

[56] References Cited UNITED STATES PATENTS 2,775,946 1/1957 Hufferd417/220 2,635,551 4/1953 De Lancey 417/220 3,028,814 4/1962 Rurnsey eta1. 417/219 3,067,693

Lambeck 417/219 Presnell 417/213 Morey 91/486 Primary Examiner-Charles.1. Myhre Assistant Examiner-Frank H. McKenzie. .lr. Attorney-Michael S.Striker [5 7 ABSTRACT A pump has a housing with a housing ring, a rotorwith pistons, and a control ring between the housing ring and the rotorso that a working space is formed between the rotor and the controlring, and an annular space is formed between the control ring and thehousing ring. The annular space is divided into first and second controlspaces, connected by throttling means. The first control space receiveshigh pressure fluid, and the second control space discharges into aconsumer line. When at high rotary speed, the pressure differentialbecomes great, the control ring is displaced to reduce the working spaceso that a substantially constant volume is pumped at different speeds. Acompensating device responds to the pressure in the consumer line tourge the control ring to increase the working space so that theinfluence of the fluid pressure and of the piston friction on thecontrol ring is compensated.

12 Claims, 7 Drawing Figures PATENTS!) JUL 3 I975 SHEU 1 U7 4 ZIP-1 3012 13 3010 Fig.2

REGULATED PUMP WITH CONSTANT DISPLACEMENT VOLUME SUMMARY OF THEINVENTION It is one object of the invention to provide a regulated pumpwhich has a substantially constant displacement volume, independently ofthe rotary speed of the pump.

Another object of the invention is to provide a pump of this type whichis of simple construction, inexpensively manufactured, and operatesreliably.

With these objects in view, the present invention arranges a throttle insuch a manner that the differential pressure upstream and downstream ofthe throttle acts directly on the control means which influences thepumpvolume.

As a result, a pump is obtained which does not require any additionalparts for a regulation depending on the pressure. Preferably, thethrottle is formed at least partly by the control means, or by gapsbetween the control means and the housing means. It is also possible toprovide the throttle passage in a controlring or in a housing ring.

In order to obtain a very exact regulation to a constant displacementvolume, irrespective of the rotary speed of the rotor, it isadvantageous to apply to the control means an additional force which isproportional to the pressure in a consumer line connected to the outletof the pump, and opposes the torque exerted by the rotor on the controlmeans due to the fluid pressure and friction of the rotor pistons on acontrol ring.

A pump of this type is particularly suited for the power steering ofmotorcars. Hydraulic power steering apparatus requires that the amountof fluid necessary for steering is already pumped at idling speed,without being substantially increased at the highest rotary speed of thepump.

An embodiment of the regulated pump, according to the invention,comprises housing means including a housing ring; a rotor mounted in thehousing means and including radial piston means; a control ring mountedin the housing ring for movement in first and second directiontransverse to the axis of the rotor, and surtrol ring is slidinglyengaged by the piston means, and

i so that the outer surface of the control ring and the inner surface ofthe housing ring define first and second control spaces located onopposite sides of a plane passing through the rotor axis transverse tothe first and second directions; biassing means mounted in the housingmeans forbiassing the control-ring to move in the first direction to afirst end position abutting the rotor on one side so that a workingspace is formed on the other side between the rotor and the innersurface of the control ring, the housing means having inlet and outletports inthe working space, 'an'd' .a conduitconnecting the outlet portwith the first control space; outlet means for a consumer apparatuscommunicating with the second control space; and throttling means. Thethrottling means are either formed by the control ring,'or by thehousing ring, or by a gap between portions of both rings, and directlyconnect the first and second control spaces so that at high rotaryspeeds, the

pressure differential between the first and second conmaintain thedisplaced volume constant at different rotary speeds of the rotor. Acompensating device is biased by pressure fluid to engage the controlring and to bias the same in the first direction.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof,will. be best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an axial sectional viewillustrating a first embodiment of the invention;

FIG. 2 is a cross-sectional view taken on line II-II in FIG. 1;

FIG. 3 is a fragmentary cross-sectional view partially in section,illustrating a modification of the embodiments of FIGS. 1 and 2;

FIG. 4- is a cross-sectional view illustrating a second embodiment;

FIG. 5 is a schematic cross-sectional view illustrating a thirdembodiment of the invention;

FIG. 6 is a schematic cross-sectional view illustrating afourthembodiment of the invention; and

FIG. 7' is a fragmentary cross-sectional view illustrat ing a fifthembodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIGS. 1 and2, a housing includes two covers 11 and 10, and a housing ring 12between the same. A rotor shaft. 14 is mounted on hearings in covers 10and 11, and has a rotor 15 located centrally in the housing ring 12.

A control ring 16 is located within the housing ring 12, surroundingrotor 15. In the embodiment of FIGS. 1 and 2, control ring 16 is mountedon a pivot 17 which is supported by the covers 10 and 11, so thatcontrol ring 16 can perform a limited angular movement relative to therotor 15 and to the housing ring 12. Control ring 16 is slightlynarrower in axial direction than housing ring 12, and the diameter ofits inner surface 20 is slightly greater than the diameter of the outersurface of rotor 15.

Rotor 15 has a series of substantially radial slots 18 in which pistons19 are mounted for radial'movement. The outer ends of pistons 19, whichare advantageously constructed as vanes, slidingly abut the innercircular surface 20 of control ring 16.

A spring 23 is provided in the annular space formed between housing ring12 and control ring 16, and urges control ring 16 to turn about pivot 17so that control ring 16 moves in one direction to an end positionabutting a ,stop22 on the inner surface 21 of housingring 12. In thisend'position, the control ring 16 is located directly adjacent one sideof rotor 15 so that at the other side of the rotor, a crescent-shapedwork space 15a is formed between the inner surface of control ring 16and the outer surface of rotor 15.

In a plane passing through the axes of rotor 15 and pivot 17 transverseto the direction of movement of control ring 16, housing ring 12 hastwo'inner projections 24 and 25v forming throttle gaps 27 and 26 withthe outer surface 16a of control ring 16. The throttle passages 26 and27 form between control ring 16 and housing ring 12, first and secondcontrol spaces 13a, 13bwhich communicate with each other through thethrottling means 24,25,26,27. The first control space 13a, in which stop22 is located, is disposed on the same side as the working space a, andthe second control space 13b is connected with an outlet 31 to aconsumer line which may lead to power steering apparatus, not shown.

In the housing cover 11, two arcuate ports 28,29 are provided, shown inchain lines in FIG. 2. The port 28, which extends over an angle of about150, is located on the same side as pivot 17, while the correspondingport 29 is located on the other side of the rotor.

The port 29 is connected by conduits 30 and 30 in covers 10 and 11 withthe first control space 13a. Conduit 30 is shown in chain lines in FIG.2.

The outer surface 16a of control ring 16 has in the second control space13b, a recess 33a engaged by a projecting part 33 of a piston 34 mountedin a cylinder bore 35 of housing ring 12. The axis of piston 34 andprojection 33 is substantially tangential to a circle having its centerin the axis of pivot 17, and passing through the rotor axis.Consequently, pressure of piston means 34,37 on control ring 16 willturn the same efficiently about pivot 17 in the same direction as spring23.

A duct 35' in housing ring 12 connects consumer line 31 and the secondcontrol space 13b with cylinder 36 on the free side of the differentialpiston 34. The cylinder portion 37 on the other side of piston 34 iswithout pressure.

In a position of rest of the pump, spring 23 urges control ring 16 toturn about pivot 44 towards an end position abutting stop 22, in whichpositionthe eccentricity of the circular control ring 16 in relation tothe rotor axis is a maximum. If control ring 16 is turned in theopposite direction against the action of spring 23, the center ofcontrol ring 16 may be brought to a position coinciding with the axis ofrotor 15.

When shaft 14 and rotor 15 are driven by a prime mover, for example, acombustion engine on amotorcar, the inlet port 28 receives pressurefluid which is pumped by the pistons 19 sweeping the working space 15a,into the outlet port 29, from where it is displaced through the conduit30 into the first control space 13a. The fluid flows then through thethrottle passages 26 and 27 into the second control space 13b, and fromthe same through the consumer outlet 31 to consumer apparatus, such aspower steering motor.

When the rotary speed of the drive motor is low, so that the pump volumeis small, the pressure drop at the throttle passages 26 and 27 is onlylow, and the entire pump fluid flows without great resistance to theconsumer line. When the rotary speed increases so that a greater volumeis pumped, the pressure differential at the throttle passages 26,27becomes greater, and the pressure in the first control space 13a becomessubstantially greater than the pressure in the second control space 13bdownstream of the throttling means 24 to 27.

Since the force exerted by the pressure fluid in the first control space13a on the control ring 16 is greater than the force exerted by thefluid in the second control space 13b on control ring 16, the same turnsabout pivot 17, compressing spring 23, and reducing the area of theworking space 15a between rotor 15 and control ring 16.

Due to the reduction of the suction and pressure areas of the workingspace 15a, the amount pumped into consumer line 31 remains substantiallythe same,

irrespective of the increase of the rotary speed of the rotor 15. Inother words, the increase of the pumped volume due to the increase ofthe rotary speed, and the reduction of the pumped volume due todisplacement of control ring 16 and reduction of working space 150,compensate each other so that a condition of equilibrium is obtained inwhich the pumped volume is almost constant.

The pistons or vanes 19 of rotor 15 exert on control ring 16 a torque,partly due to friction, so that the same is urged to turn about pivot 17to a position reducing the working space 15a while compressing spring23. The influence of this torque is undesirable, since it constitutes aregulation of the output volume not only depending on the rotary speedof rotor 15, but also on the pressure. This torque is compensated by thecompensating device including differential piston 34,35 since the forceexerted by projection 33 on control ring 16 is proportional to thepressure in the consumer line 31 and in the second control space 13b.The force exerted by projection 37 produces a compensating torquetending to turn control ring 16 in clockwise direction about pivot 17for increasing again the working space 15a. Due to the position of thecompensating device, the regulation of the pump is only speeddepending,and not pressure depending.

The use of portions 25,24 of the housing ring, and the correspondingportions of control ring 16 for providing the throttling means creatingthe necessary differential pressure, results in an extremely simple andinexpensive construction.

Since spring 23 and the piston means 34,33 act in the same direction oncontrol ring 16, it is possible to combine the biassing means for thecontrol ring 16 with the compensating device, and such a modification isillustrated in FIG. 3. Parts of the pump not shown in the fragementaryview of FIG. 3, are constructed as illustrated in FIGS. 1 and 2.

A differential piston 40 has a piston part 40' of great diameter guidedin a cylinder bore provided in a screw 41 which is screwed into a borein the housing. The smaller piston portion 40"extends tangential to thecontrol ring 16. In axial direction of the differential piston 40,40, aseparate head 43 is provided which is located in recess 32 of controlring 16, and can be slightly displaced due to the rounded shape of head43. Between head 43 and the housing, a spring 44 is arranged whichperforms the function of the spring 23 shown in FIG. 2, but the force ofthe spring is directed in the same direction as the force of thedifferential piston The cylinder space 45 is connected by a duct withthe second control space 13b, where the pressure of the consumer line 31prevails due to the provision of the throttling means 24 to 27.

A safety valve 47, which opens into a return duct 48, is connected by aconduit 46 with the pressure chamber 45. When the pressure in theconsumer line 31 exceeds a predetermined maximum pressure, safety valve47 opens, and the pressure in cylinder space 45 drops, together with thepressure in control space 13b. Since the pressureacting on control ring16 in the first control space 13a is higher, control ring 16 is turnedabout pivot 17 against the action of spring 44, if necessary to aposition in which its center coincides with the rotor axis, so that nofluid is pumped.

The embodiment of FIG. 4 is schematically illustrated, and it will beunderstood that the omitted parts corresponds to the construction shownin FIGS. 1 and 2. The housing ring 12' has two confronting straightparallel guide faces 50, engaged by corresponding straight oppositeguide faces provided on control ring 16. The pivot 17 of FIGS. 1 and 2is omitted, and the movement of control ring 16 due to the action ofspring 23', or due to the fluid pressure in the control space 13a, isrectilinear. A conduit 52 is provided in the housing ring 12, and has anarrow throttle passage 51. Conduit 52 is arranged in housing ring 12 toconnect the first control space 13a with the second control space 13b sothat a pressure differential is created between the two control spaceson opposite sides of control ring 16'. Adjusting means are provided forvarying the free cross section of the throttling passage 51, and includea needle 51 having a threaded head 51a engaging a threaded bore in thehousing ring 16' so that the point of the needle can be moved into andout of the throttling passage 51 for adjusting the throttle.

The torque exerted by rotor 15 on the control ring 16, which may causejamming, is balanced by the pressure in balancing chambers 53 providedin the guide faces 50. The pressure differential between the controlspaces 13a and 13b, directly acts on the control ring 16', without anyintermediate or conduit linkage. When the crosssection or throttlepassage 51 is adjusted by needle 51', the differential pressure actingon control ring 16' is also adjusted, so that any desired constantdisplacement volume can be obtained by adjustment of the throttle.

Another embodiment of the invention is schematically illustrated in FIG.5. The projections 26 and 27 on the inner surface of housing ring 12'cooperate with the outer surface of control ring 16' to form twothrottling passages, as described with reference to FIG. 2. Instead ofthe pivot 17, control ring 16' has two diametrically projecting pistonportions 55 and 56 provided in cylinder bores of housing ring 12'', andspring 23" acts on piston 56 to urge control ring 16" in one direction.The control spaces 13a and 13b operate as described with reference toFIGS. 1 and 2.

Two compensating devices 57 and 58 are diametrically arranged and havepiston portions 57a and 58a movable in substantially tangentialdirection of control ring 16", which is engaged by the piston portions57a and 58a. The compensating devices 57 and 58 are connected with thesecond control space 131;. The provision of two diametrically arrangedcompensating devices 57 and 58, instead ofonly one, as: in FIGS. 1 and2, has the advantage that jamming of the pistons and 56 in thecorresponding bore of housing ring 12', is prevented.

In the schematically illustrated embodiment of FIG. 6, the pivot 17 isalso omitted, and the aligned slots 60 and 61 are provided in thecontrol ring 60". Guide pins 62,63 are secured to the housing, notshown, and project into the slots 60 and 61 so that the control ring 60"is guided for rectilinear movement. Compensating devices, as shown inFIG. 5, may be provided, but are not shown. The arrangement of thethrottling. gaps 26 and 27 correspond to the construction described withreference to FIG. 2. i

In the embodiment of FIG. 7, the throttling means is provided in thecontrol ring 16". A straight conduit 66 extends along a chord in controlring 16"", and opens into control spaces 13a and 13b. A narrow throttlepassage produces a pressure differential between the control spaces 13aand 13b. Sealing means 67 and 68 are located in recesses 69,70 ofhousing ring 12". The differential pressure between control spaces 13aand 13b urges the sealing means 67 and 68 into fluid-tight engagementwith the outer surface of control ring 16"" and the surfaces of recesses69,70, so that the control spaces are fluid tightly separated from eachother. A pivot 17 supports the control ring 16 for angular movement, asdescribed with reference to FIG. 2. Spring 23 urges control ring 16""into abutment with stop 22 on housing ring 12"". Sealing means 67,68 maybe constructed as elastic rolls, or as sealing lips.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types of.regulated pumps differing from the types described above.

While the invention has been illustrated and described as embodied in aregulated pump with constant displacement volume irrespective of therotary speed, it is not intended to be limited to the details shown,since various modifications and structural changes may be made withoutdeparting in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims.

We claim:

1. Regulated pump with constant displacement volurne, comprising housingmeans including a housing ring; a rotor mounted in said housing meansfor rotation about an axis, and including radial piston means; a controlring mounted in said housing means within said housing ring for movementin first and second opposite directions transverse to said axis, andsurrounding said rotor so that the inner surface of said control ring isslidingly engaged by said piston means, and so that the outer surface ofsaid control ring and the inner surface of said housing ring definefirst and second control spaces located on oppositesides of a planepassing through'said axis transverse to said first and seconddirections; biasing means mounted in said housing means for biasing saidcontrol ring to move in said first direction to a first end positionadjacent to said rotor on one side so that a working space is formed onthe other side between said rotor and the inner surface of said controlring; said housing means having inlet and outlet ports in said workingspace, and a conduit connecting said outlet port with said first controlspace; outlet means for a consumer apparatus communicating with saidsecond control space; throttling means formed by at least one of saidrings and directly opening into said first and second control spaces sothat at high rotary speeds the pressure differential between said firstand second control spaces moves said control ring in said seconddirection against said biasing means toward the other side of said rotorwhereby said working space is reduced for maintaining the displacedvolume constant at different rotary speeds of said rotor, and wherebyfluid pressure and friction of said piston means on said control ringproduces a force acting in said second direction on said control ring;and a compensating device mounted in said housing ring and including apressure responsive means communicating with said second control spaceand biased by the pressure in the same to engage said control ring andto bias the same in said first direction for compensating said forceproduced by said fluid pressure and friction of said piston means onsaid control ring.

2. Regulated pump as claimed in claim 1 wherein said throttling meansincludes two diametrically disposed throttles located in said plane andformed by portions of said housing ring and of said control ring.

3. Regulated pump as claimed in claim 1 comprising a pivot located insaid plane and mounted in said housing means eccentric to said axis forsupporting said control ring for angular movement between said first andsecond end positions.

4. Regulated, pump as claimed in claim 1, wherein said throttling meansincludes adjusting means for varying the throttling flow cross section.

5. Regulated pump as claimed in claim 1, wherein said biassing meansincludes a spring acting on said pressure responsive means.

6. Regulated pump as claimed in claim 1 wherein said compensating deviceincluding a cylinder formed in said housing ring, a pressure responsivepiston in said cylinder having a portion projecting into engagement withsaid control ring, and a duct formed in said housing means connectingsaid cylinder with said second control space so that said control ringis biassed to move in said first direction for compensating a torqueproduced thereon by fluid pressure, and by friction of said piston meansand acting in said second direction on said control ring.

7. Regulated pump as claimed in claim 6, wherein said projecting portionof said piston of said compensating device acts on said control ring insubstantially tangential direction.

8. Regulated pumr as claimed in claim 6 comprising at least twocompensating devices located on opposite sides of another planepassing'through said'axis perpendicularly to said plane; wherein saidcontrol ring has two diametrically disposed outward projecting pistonportions located in said other plane; wherein said housing ring has twodiametrically disposed bores receiving said piston portions for guidingsaid control ring for straight movement in said first and seconddirections; and wherein said biassing means is a spring located in oneof said bores for urging said control ring to move in said firstdirection.

9. Regulated pump as claimed in claim 1, comprising a pivot located insaid plane and mounted in said housing means eccentric to saidaxis forsupporting said control ring for angular movement between said first andsecond end positions; and wherein said throttling means includes twodiametrically disposed throttles located in said plane.

10. Regulated pump as claimed in claim 1, comprising a pivot pin locatedin said plane supported in said housing; and wherein said control ringhas a bearing bore in which said pivot pin is located eccentric to saidaxis for supporting said control ring for angular movement between saidfirst and second positions.

11. Regulating pump as claimed in claim 10, wherein said compensatingdevice includes means for guiding said pressure responsive meanstangentially to a circle having the center in said pivot pin and passingthrough said axis.

12. Regulated pump as claimed in claim 1, wherein said throttling meansinclude two diametrically disposed throttles located in said plane.

1. Regulated pump with constant displacement volume, comprising housingmeans including a housing ring; a rotor mounted in said housing meansfor rotation about an axis, and including radial piston means; a controlring mounted in said housing means within said housing ring for movementin first and second opposite directions transverse to said axis, andsurrounding said rotor so that the inner surface of said control ring isslidingly engaged by said piston means, and so that the outer surface ofsaid control ring and the inner surface of said housing ring definefirst and second control spaces located on opposite sides of a planepassing through said axis transverse to said first and seconddirections; biasing means mounted in said housing means for biasing saidcontrol ring to move in said first direction to a first end positionadjacent to said rotor on one side so that a working space is formed onthe other side between said rotor and the inner surface of said controlring; said housing means having inlet and outlet ports in said workingspace, and a conduit connecting said outlet port with said first controlspace; outlet means for a consumer apparatus communicating with saidsecond control space; throttling means formed by at least one of saidrings and directly opening into said first and second control spaces sothat at high rotary speeds the pressure differential between said firstand second control spaces moves said control ring in said seconddirection against said biasing means toward the other side of said rotorwhereby said working space is reduced for maintaining the displacedvolume constant at different rotary speeds of said rotor, and wherebyfluid pressure and friction of said piston means on said control ringproduces a force acting in said second direction on said control ring;and a compensating device mounted in said housing ring and including apressure responsive means communicating with said second control spaceand biased by the pressure in the same to engage said control ring andto bias the same in said first direction for compensating said forceproduced by said fluid pressure and friction of said piston means onsaid control ring.
 2. Regulated pump as claimed in claim 1 wherein saidthrottling means includes two diametrically disposed throttles locatedin said plane and formed by portions of said housing ring and of saidcontrol ring.
 3. Regulated pump as claimed in claim 1 comprising a pivotlocated in said plane and mounted in said housing means eccentric tosaid axis for supporting said control ring for angular movement betweensaid first and second end positions.
 4. Regulated pump as claimed inclaim 1, wherein said throttling means includes adjusting means forvarying the throttling flow cross section.
 5. Regulated pump as claimedin claim 1, wherein said biassing means includes a spring acting on saidpressure responsive meaNs.
 6. Regulated pump as claimed in claim 1wherein said compensating device including a cylinder formed in saidhousing ring, a pressure responsive piston in said cylinder having aportion projecting into engagement with said control ring, and a ductformed in said housing means connecting said cylinder with said secondcontrol space so that said control ring is biassed to move in said firstdirection for compensating a torque produced thereon by fluid pressure,and by friction of said piston means and acting in said second directionon said control ring.
 7. Regulated pump as claimed in claim 6, whereinsaid projecting portion of said piston of said compensating device actson said control ring in substantially tangential direction.
 8. Regulatedpump as claimed in claim 6 comprising at least two compensating deviceslocated on opposite sides of another plane passing through said axisperpendicularly to said plane; wherein said control ring has twodiametrically disposed outward projecting piston portions located insaid other plane; wherein said housing ring has two diametricallydisposed bores receiving said piston portions for guiding said controlring for straight movement in said first and second directions; andwherein said biassing means is a spring located in one of said bores forurging said control ring to move in said first direction.
 9. Regulatedpump as claimed in claim 1, comprising a pivot located in said plane andmounted in said housing means eccentric to said axis for supporting saidcontrol ring for angular movement between said first and second endpositions; and wherein said throttling means includes two diametricallydisposed throttles located in said plane.
 10. Regulated pump as claimedin claim 1, comprising a pivot pin located in said plane supported insaid housing; and wherein said control ring has a bearing bore in whichsaid pivot pin is located eccentric to said axis for supporting saidcontrol ring for angular movement between said first and secondpositions.
 11. Regulating pump as claimed in claim 10, wherein saidcompensating device includes means for guiding said pressure responsivemeans tangentially to a circle having the center in said pivot pin andpassing through said axis.
 12. Regulated pump as claimed in claim 1,wherein said throttling means include two diametrically disposedthrottles located in said plane.